[Buildroot] How to get the (GIT) Version string into the source code

[Wolfgang Grandegger]

Hello,

I'm looking for a simple method to get the package version string used
by buildroot into the source code of that package. Unfortunately, the
GIT version information is stripped off. For the moment, I use the name
of the build directory and pass it to the code via Makefile, but maybe
there is a more elegant version.

Wolfgang